[superfund explanation of significant differences for ... · the crystal chemical company superfund...

EPA SuperfundExplanation of SignificantDifferences forRecord of Decision:

Crystal Chemical Company Superfund SiteHouston, Texas03/119/97

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CRYSTAL CHEMICAL COMPANYSUPERFUND SITE

TABLE OF CONTENTSPAGE

SECTION

I. STATEMENT OF PURPOSE 1

CT. INTRODUCTION 1

m. SITE HISTORY AND ORIGINALLY SELECTED REMEDIES 4

IV. DESCRIPTION OF AND BASIS FOR THE SIGNIFICANT DIFFERENCE 4

V. PUBLIC PARTICIPATION ACTIVITIES

VI. STATE COMMENTS

Vn. STATUTORY DETERMINATION

FIGURES

1 SITE AREA MAP

2 GEOLOGIC CROSS-SECTION

3 AREAL EXTENT OF TI ZONE AND ESTIMATEDLOCATION OF SLURRY WALL

APPENDICES

A RESPONSIVENESS SUMMARY

B STATE OF TEXAS CONCURRENCE LETTER

C ADMINISTRATIVE RECORD INDEX

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EXPLANATION OF SIGNIFICANT DIFFERENCESTO THE SEPTEMBER 1990 RECORD OF DECISION

CRYSTAL CHEMICAL COMPANY SUPERFUND SITEHOUSTON, TEXAS

L STATEMENT OF PURPOSE

This document explains the differences between the ground water remedy being implementedand the ground water remedy identified in the September 1990 Record of Decision (1990 ROD) forthe Crystal Chemical Company Superfund Site.

During the course of the design for the extraction and treatment of arsenic-contaminatedground water remedy identified in the 1990 ROD, the U. S. Environmental Protection Agency (EPA)and the Texas Natural Resourw Conservation Commission (TNRCC) determined that restoration ofthe ground water is technically impracticable for portions of the Crystal Chemical CompanySuperfund site. Therefore, EPA has determined that the applicable or relevant and appropriaterequirement (ARAR) for ground water restoration to the Maximum Contaminant Level (MCL) of50 ^ig/1 for arsenic will be waived and a sluny wall will be constructed around the portions of the sitewhere ground water cannot be restored. The extraction and treatment of arsenic-contaminatedground water remedy will be implemented on the remainder of the site, as specified in the 1990 ROD.

H. INTRODUCTION

The Crystal Chemical Company Superfund site (Crystal Chemical site) is located at 3502Rogerdale Road, in southwestern Houston, Harris County, Texas. The Crystal Chemical site isbound on the west by the Harris County Flood Control Channel and lies immediately south of theWestpark Drive extension (Figure 1).

EPA is the lead agency for the Crystal Chemical site, and the State of Texas, throughTNRCC, has been involved in all aspects of site activities. Southern Pacific Transportation Companyhas been identified as one of the potentially responsible parties for the Crystal Chemical site, and EPAhas authorized Southern Pacific Transportation Company through an Administrative Order onConsent and an Unilateral Administrative Order to design and implement the ground water remedyfor the Crystal Chemical site, as set forth in the 1990 ROD.

This Explanation of Significant Differences (ESD) is prepared in accordance with Section117(c) of the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA),as amended by Superfund .Amendments and Reauthorization Act, 42 U.S.C. § 9617(c), whichprovides that, after adoption of a final remedial action plan, if any remedial action is taken and if suchaction differs in any significant respects from the final plan, EPA shall publish an explanation of thesignificant differences and the reasons such changes were made.

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0This ESD is necessitated by the findings made during the course of the remedial design of the ^

ground water extraction and treatment remedy. The results of the design investigations and the ^findings are presented in the Assessment of the Technical Impracticability of Ground-Water 0Remediation, February 1996 for the Crystal Chemical site (TI Assessment). Specifically, it hasbeen determined that restoration of the arsenic-contaminated ground water is technicallyimpracticable due to hydrogeologic as well as contaminant-related factors for portions of the CrystalChemical site. Therefore, EPA has determined that the ARAR for the ground water restoration tothe MCL of 50 ug/1 for arsenic will be waived and a slurry wall will be constructed to protect humanhealth and the environment on the portions of the site that cannot be restored. These alternativeremedial strategies were selected from the list of ground water contingency measures identified in the1990 ROD (pages 95 and 96). The ground water extraction and treatment remedy will beimplemented on the remainder of the site, as specified in the 1990 ROD.

In accordance with the National Oil and Hazardous Substances Pollution Contingency Plan,40 CFR §300.825(a)(2), this ESD and the supporting information EPA relied upon in preparing theESD, including the TI Assessment, will become part of the Administrative Record for the CrystalChemical site. The Administrative Record file for the Crystal Chemical site is available at thefollowing locations:

U.S. EPA. Region 6Library, 12th floor (6MD-H)1445 Ross AvenueDallas, Texas 75202-2733(214) 665-6424 or 665-6427facsimile (214) 665-2146Hours of Operation: Monday through Friday 7:30 am-4:30 pm

Judson Robinson-Westchase Library3223 WilcrestHouston, Texas 77042(713)784-0987Hours of Operation: Monday 12:00 pm-9:00 pm; Tuesday 10:00 am- 9:00 pm; Wednesday10:00 am"6:00 pm; Thursday 12:00 pm-9:00 pm; and, Friday/Saturday 10:00 am-6:00 pm

Texas Natural Resource Conservation Commission12118 North IH 35Technical Park Center, Room 190, Building DAustin, Texas 78753(512)239-2920Hours of Operation: Monday through Friday 8:00 am-5:00 pm

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IDL SITE mSTORY AND ORIGINALLY SELECTED REMEDIESVsQ

Crystal Chemical Company produced arsenical, phenolic, and amine-based herbicides from ^1968 to 1981. Operation and maintenance problems at the Crystal Chemical facility during the late1970s resulted in several violations of the State of Texas' environmental standards, and in September1981, Crystal Chemical Company filed for bankruptcy and abandoned the site. In 1983, the CrystalChemical property was added to the National Priorities List, qualifying the site for investigation andremediation under CERCLA, more commonly known as Superfund.

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In September 1990, EPA issued the ROD that addressed soil and ground watercontamination. The selected remedy for soil called for the excavation of offsite soils contaminatedwith arsenic greater than 30 piuts per million (ppm), treating all the soils contaminated with arsenicgreater than 300 ppm with a process called in-situ vitrification, and capping the entire site after thesoils treatment had been completed. Due to the unavailability of the in-situ vitrification technology,EPA selected a new soil remedy in a ROD amendment issued in June 1992. The soil consolidationand capping remedy was completed in September 1995.

The remedy selected in the 1990 ROD for ground water called for the extraction andtreatment of arsenic-contaminated ground water. The remediation goal specified in the 1990 RODfor the affected ground water zones is 50 ug/1, the MCL for arsenic. The 1990 ROD also includedseveral contingency measures that could be implemented if an extraction and treatment system wouldnot produce the remediation goals set for the Crystal Chemical site.

IV. DESCRIPTION OF AND BASIS FOR THE SIGNIFICANT DIFFERENCE

The 1990 ROD states that the goal of the ground water remedy is to restore the ground waterto a useable state, i.e., removing the arsenic to the MCL of 50 (ig/l. However, the 1990 RODindicates that due to the uncertainty as to whether the remedy will be able to meet the remediationgoal of the MCL for arsenic, contingency measures and goals may replace the selected remedy andgoals. The contingency measures specified in the 1990 ROD were:

1) discontinuing operation of extraction wells in areas where remediation goals havebeen attained;

2) alternating pumping at wells to eliminate stagnation points; and/or,

3) establishing an Alternative Concentration Limit for arsenic provided compliance withCERCLA Section 121 (d)(2)(B)fii) can be demonstrated;

4) waiving the ground water ARAR for those portions of the aquifer based on thetechnical impracticability of achieving further contaminant reduction;

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5) implementing low level pumping as a long-term gradient control or construction of ^oa containment measure such as a slurry wall; and/or, ^

r—lo6) implementing .additional source control treatment to further reduce arsenic migration

to ground water.

At the time of the 1990 ROD, EPA called for investigations and evaluations necessary todesign the extraction and treatment system for the ground water remedy. Through an AdministrativeOrder on Consent, EPA authorized Southern Pacific Transportation Company to undertake, withEPA oversight, the investigations and evaluations necessary to design an efficient and effectiveground water extraction and treatment system.

During the course of the design investigations and evaluations, data indicated that portionsof the site's contaminated ground water zones could not be restored. The portions of the site thatcannot be remediated (the technical impracticability (TI) zone) consists of splay deposits, or off-channel deposits. These splay or off-channel deposits consist of sandy material with an abundanceof fine-grained material (clay and/or silt). The other portion of the site, which is not part of the TIzone and is therefore not affected by this ESD, consists of a subsurface stream channel. Thesubsurface stream channel contains more sand and less fine-grained material, and this portion of thesite can likely be restored through the extraction and treatment remedy based on the informationcollected and evaluated (Figures 2 and 3).

The findings of the investigations and evaluations are presented in the TI Assessment for theCrystal Chemical site. Factors providing the basis for the TI waiver include the following:

1) The complexity of the site geology;

2) the majority of the arsenic is in the fine-gmined splay or off-channel deposits;

3) lab and field testing indicates that the arsenic has adsorbed on to the fine-grainedsediments of the splay or off-channel deposits;

4) over 700 million gallons of water would have to be extracted to try to achieve theremediation goal;

5) the slow release of arsenic from the fine-grained sediments will limit the rate andquantity of arsenic that can be removed by extracting the ground water; therefore,

6) a range from 200 to 650 years is the minimum time estimated to restore the groundwater zones, if they could be restored at all.

The timing of this TI decision is consistent with EPA's current program guidance on suchwaivers, "Guidance for Evaluating the Technical Impracticability of Ground Water Restoration(OSWER Directive 9234.2-25, September, 1993). The guidance states that a TI decision may be

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FIGURE 2GEOLOGIC CROSS-SECTION

(3^g/L)

CPT62B

(230.000^9/L)T 1 A

(236.000^/L)T 1 B

(20.40<WL)MW-1A

CHANNEL AND LEVEE AND BARDISTRIBUTARY-MOUTH BAR

EXPLANATION

SSS SC - CLAYEY SANDStttWra

I - : - : [ SM - SILTY SANDS

f - — ) SP - POORLY GRAJ3ED SANDSL——•—hJ

CL-CLAYS

g g ML - INORGANIC KILTS AND VERY FINE SANDS

r " J DISTRIBUTARY MOUTH DEPOSIT (SP/SM)

^ NO RECOVERY

(20,400 ug/L) CONCENTRATION OF ARSENIC IN WATER

Sh HORIZONTAL BEDDED SANDS

Sl LAMINATED SAT^ DS

t FINING-UPWARD SEQUENCES

0 20 ftNO VERTICAL EXAGGERATION

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FIGURE 3 - AREAL EXTENT OF TI ZONEAND ESTIMATED LOCATION OF SLURRY WALL

f . • - | AREA OT TI DISTRIBUTION IN[___J 15-FT AND 35-fT ZONES15-FT AND 35-fT ZONES

•5<7-*^ 50 ppb ARSENtC CONCEmiVJION CONTOUR

| | FORMER STRUCTURES JE PONOS

9 BORINGS USED M TRANSECT 1

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made prior to implementing the remedy provided such a TI decision is adequately supported bydetailed site-specific data and analyses. ^o

^oThe detailed technical demonstration that serves as the basis for the TI decision at the Crystal ^

Chemical site is provided m the TI Assessment, prepared by Southern Pacific TransportationCompany. The TI Assessment presents a detailed analysis of information collected prior to theissuance of the ROD, as well as information collected during the design investigations.

During the course of the implementation of the soil remedy (completed in September 1995),contaminated soils associated with two of the three onsite wastewater storage/treatment ponds wereexcavated and placed under the engineered, low permeability cap that was constructed over the entireCrystal Chemical site. Based on the depth of contamination, excavation from the third pond was notnecessary. All source control measures that could reduce the migration of arsenic to the groundwater have been implemented at the Crystal Chemical site. Therefore, according to the ROD, theground water contingency measure calling for the implementation of additional source control (RODgromdwater contingency measure ^6) has been carried out.

As a result of EPA.'s conclusion that restoration of the ground water is technicallyimpracticable for portions of the Crystal Chemical site, EPA has determined that the ARAR forground water restoration will be waived (ROD groundwater contingency measure H4) and a slurrywall will be constructed around the portions of the site where ground water cannot be restored (RODgroundcolor contingency measure #5). See Figure 3 for the illustration of the TI zone and locationof the slurry wall. The extraction and treatment of arsenic-contaminated ground water remedy willbe implemented on the remainder of the site.

Although the 1990 ROD indicates that there will be operation and monitoring of theextraction and treatment system for 10 years prior to consideration of the contingency measures,implementation of the extraction and treatment remedy and monitoring for a 10-year period is notnecessary to determine that the remedy is incapable of achieving the remediation goal in the TI zone.EPA already has adequate information to support its determination that a TI waiver is appropriate.

The Texas Natural Resource Conservation Commission (TNRCC) has reviewed the TIAssessment and agrees that the data support the findings that ground water restoration on portionsof the Crystal Chemical site is technically impracticable. TNRCC has also concurred with EPAregarding the construction of the slurry wall around the TI zone.

V. PUBLIC PARTICIPATION ACTIVITIES

During the preparation of the ROD, EPA held a public comment period from June 11,1990through July 11, 1990. Informal open houses were held in the Houston area on two separateoccasions: April 10 and June 5, 1990. Additionally, a public meeting was held on June 21, 1990.EPA responded to comments received during the public meeting as well as the public comment periodin the Responsiveness Summary, which is an attachment to the ROD.

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During the preparation of the ROD amendment for the soil remedy, EPA held a public <§comment period from February 24, 1992 through March 24, 1992. An informal open house was held ôn February 20, 1992, with the public meeting being held on March 19, 1992. EPA responded tocomments received during the public meeting as well as the public comment period in theResponsiveness Summary, which is an attachment to the June 1992 ROD amendment for the soilremedy.

oS

An open house was held on October 13, 1994 to update the community on the remedialdesigns for the soil and ground water remedies for the Crystal Chemical site.

A notice of this Explanation of Significant Differences and a summary of the differencesbetween the ground water remedy being proposed and the ground water remedy identified in the 1990ROD was published in the Houston Chronicle on July 12, 1996. Approximately 1300 fact sheetssummarizing the proposed changes and requesting public participation were mailed, and EPA invitedpublic comment from July 15, 1996 until August 15, 1996. All written comments submitted havebeen responded to in the attached Responsiveness Summary.

VL STATE COMMENTS

The State's letter expressing its concurrence with this ESD is attached.

Vn. STATUTORY DETERMINATION

Considering the new information developed during the remedial design for the ground waterremedy described in the ROD, specifically the technical impracticability of restoring the ground wateron portions of the site, EPA believes that the remedy remains protective of human health and theenvironment. Furthermore, the 1990 ROD remains protective and continues to meet ARARsidentified in the 1990 ROD that are not being waived. The revised remedy utilizes permanentsolutions to the maximum extent practicable for this site and is cost-effective. It complies with theNational Oil and Hazardous! Substances Pollution Contingency Plan and other federal and staterequirements that are applicable or relevant and appropriate to this remedial action.

^Tane^. Sagtâw ^ff Reônal 4@mimstrator

Date

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APPENDIX A

EXPLANATION OF SIGNIFICANT DIFFERENCES FOR THECRYSTAL CHEMICAL COMPANY SUPERFUND SITE

RECORD OF DECISIONRESPONSIVENESS SUMMARY

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RESPONSIVENESS SUMMARY FOREXPLANATION OF SIGNIFICANT DIFFERENCES

TO THE SEPTEMBER 1990 RECORD OF DECISIONCRYSTAL CHEMICAL COMPANY SUPERFUND SITE

HOUSTON, TEXAS

The public comment period for the Explanation of Significant Differences to the CrystalChemical Company Superfumd site September 1990 Record of Decision was held from July 15,1996 to August 15, 1996. The EPA received no requests for a public meeting during the publiccomment period. The only comments received during the public comment period were submittedby Vinson & Elkins, Attorneys at Law, on behalf of their client Mr. Theodore Levy. Mr. Levy,now deceased, owned property north of the site. These comments are being addressed in thisResponsiveness Summary.

Comment 1; EPA must use the [Record of Decision] Amendment process to grant the[technical impracticability] waiver.

The Guidance/or Evaluating the Technical Impracticability of Ground-WaterRestoration" (OSWER Directive 9234.2-25, September 1993) identifies an Explanation ofSignificant Differences (ESD) as a mechanism by which a technical impracticability (TI) waivercan be invoked. The directive does state that public notice and opportunity for comment shouldbe provided if an ESD is used to grant the TI waiver. Pursuant to the directive, the EPA hasprovided public notice and opportunity for comment since an ESD is being used to invoke the TIwaiver.

The requirements for issuing an ESD and issuing a Record of Decision (ROD)Amendment pursuant to the National Oil and Hazardous Substances Pollution Contingency Plan(NCP) differ essentially in that a ROD Amendment is subject to public comment. The ROD issuedin September 1990 for the Crystal Chemical Company Superfund site identified several groundwater contingency measures that could be implemented if an extraction and treatment systemwould not attain the remediadon goals set for the Crystal Chemical Company site, andopportunity for public comment was provided for the ground water contingency measuresidentified in that 1990 ROD. The contingency measures in the 1990 ROD included containmentthrough use of a slurry wall. The EPA also issued a notice of availability and brief description ofthe proposed ESD for the Crystal Chemical Company site ground water remedy in the HoustonChronicle, a major local newspaper of general circulation. Approximately 1300 fact sheetssummarizing the changes and requesting public participation were mailed. The proposed ESDand supporting information were available to the public in the administrative record.

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Unfortunately, property adjacent to the site has been affected by the ground watercontamination associated with the Crystal Chemical Company site. Regardless of whether the TIwaiver was invoked or the 1990 ROD extraction and treatment remedy was implemented on allportions of the site, the adjacent property would be affected by the remedial action for the groundwater contamination. Under the design plan for the extraction and treatment remedy, installationof two or three extraction wells were planned on the adjacent property for long-term operation.During the development of this design, however, it was determined that the extraction andtreatment remedy would be unable to attain EPA's goal of restoring contaminated ground waterat the Crystal Chemical Company site within a reasonable time frame. Therefore, after carefulconsideration, the EPA has selected an alternative remedial strategy that is technically practicable,protective of human health and the environment, and satisfies the statutory and regulatoryrequirements of the Superfund program. This alternative remedial strategy includes theconstruction of a slurry wall across Westpark Drive and onto the adjacent property. The slurrywall will contribute to the long-term management of contaminant migration by limiting the furthercontamination of ground water. Effective source containment will permit restoration of theportion of the aqueous plume that lies outside the containment area.

Comment 2: The TI waiver cannot be granted because EPA has not demonstrated that anenhancement or augmentation of the selected remedy could not attain thegroundwater cleanup standard.

With the issuance of this ESD, the EPA concludes the culmination of approximatelythirteen years of investigations and studies in connection with the Crystal Chemical Company site.Pursuant to the Guidance for Evaluating the Technical Impracticability of Ground-WaterRestoration " (OSWER Directive 9234.2-25, September 1993), the Assessment of the TechnicalImpracticability of Ground-Water Remediation for the Crystal Chemical Superfund Site,February 1996 (TI Assessment) was drafted by Southern Pacific Transportation Company inconsultation with EPA, and v/as ultimately approved by the EPA. EPA representatives from thisregional office as well as from EPA's headquarters in Washington, D.C., participated in theevaluation and review of the Crystal Chemical Company site and of this document.Representatives from EPA's Office of Research and Development, Technical Support Project atthe Robert S. Kerr Environmental Research Laboratory also fully participated in the evaluationand review of the site, the ground water remedy, the ground water contingency measures, and theTI waiver request.

In pursuit of the statutory preference for treatment and a permanent solution to the CrystalChemical Company site, EPA. has been receptive to new technologies as well as innovativeapproaches to addressing the contamination at the Crystal Chemical Company site during the pastthirteen years. In portions of the site where it has been determined that restoration of the groundwater is technically practicable, a contaminated ground water extraction and treatment system has

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been constructed and is operational. It is estimated that to reach the ground water remediationgoals for areas outside the proposed slurry wall, the water treatment plant will be treating theextracted ground water (at approximately 5-10 gallons per minute) for the next 15 years.

During the development of the TIAssessment for areas of the site where groundwaterrestoration is not technically practicable, initial bench tests (e.g., soil column leaching tests) toassess the viability of aquifer extraction enhancement were conducted. In fact three methods forthe in-situ treatment of arsenic-bearing ground water were postulated: 1) a soluble ferric ironcomplex would be injected into the contaminated aquifer; breakdown of the complex would allowprecipitation of ferric hydroxide at near-neutral pH, and arsenic would be coprecipkated; 2)ground water pumped from the aquifer would be treated on the surface to produce a ferrichydroxide precipitate containing arsenic; the ferric hydroxide, if present as a colloidal suspension(a hydrosol), could be injected into the contaminated aquifer; and 3) aqueous ferric sulphatewould be injected into the aquifer in a geometric pattern with compressed air to oxidize residentarsenite to arsenate while reacting with both inorganic and organic arsenic species. The testingand studies concluded that arsenic could not be recovered from saturated soils to any significantdegree. A multi-year testing program (from further lab and bench scale tests to actual field pilottests) would be needed in order to design a full-scale aquifer remediation program usingchemically enhanced desorption or dissolution and mobilization of the arsenic at the CrystalChemical Company site. Even after designing a full scale system, uncertainties regarding theability of this remedial strate^ to achieve the ground water remedial goals in the field wouldremain due to hydrogeologic factors (i.e., subsurface heterogeneities and abundance of fine grainmaterials [clay and/or silt]) and contaminant-related factors.

As an attachment to the comments, a contractor provided a document which discussed thepossibility of similar enhancements to the extraction and treatment remedy for the CrystalChemical Company site. The contractor indicated that its "analysis and groundwater-flowmodeling of the Crystal Chemical situation clearly showed that hydraulic control of ground waterflow and transport could be achieved at the Crystal Chemical site through proper design, number,and placement of wells." Previous modeling done for the Crystal Chemical Company site inrelation to the TI evaluation showed that a range from 200 to 650 years is the minimum timeestimated to restore the ground water zones, if they could be restored at all. Although themodeling done in relation to the TI evaluation did not include the addition of a chemical agent toaid in the extraction of contamination, the fact that it predicted very long restoration time frames(e.g., longer than 250 years) seems to indicate the presence of hydrogeologic and/or contaminant-related constraints to remediation. In addition, nowhere in the contractor's document is a singleexample cited where arsenic of any form has been successfully removed from an aquifer to theCrystal Chemical Company site remediation goal or to any other goal. Therefore, until theconclusion and evaluation of a multi-year testing program as discussed above, the ability of thecontractor's proposed insitu extraction enhancements to attain the ground water remediationgoals would not be known. The EPA has determined that it is more appropriate to go forwardwith a remedy which has been demonstrated to be effective.

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Comment 3: The administrative record does not support the action EPA proposed ir>because it does not include any evidence indicating an enhanced desorption 2remedy is impracticable. °

The administrative record does contain [as required in CERCLA § 113(k)(l)] thedocuments that form the basis for the selection of the response action. As discussed in the Officeof Solid Waste and Emergency Response Directive # 9833.3A-1 (Final Guidance onAdministrative Records for Selecting CERCLA Response Actions), the administrative record filehas been amended to include all of the comments submitted during the formal public commentperiod. The information submitted during the formal public comment period does not support theproposition that enhanced desorption is practicable for the Crystal Chemical Company site. Thespeculative nature of the technology and the lack of specific and/or demonstrated application tothe Crystal Chemical Company site does not Justify the additional time and resources needed topursue enhanced desorption, especially given the thirteen years already expended in studying theCrystal Chemical Company site in pursuit of a remedy. The EPA has selected an alternativeremedial strategy that is technically practicable, protective of human health and the environment,and satisfies the statutory and regulatory requirements of the Superfund program.

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APPENDIX B

STATE OF TEXAS CONCURRENCE LETTER

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Barry R. McBee, ChairmanR. B. "Ralph" Marquez, CommissionerJohn M. Baker, CommissionerDan Pearson, Executive Director

TEXAS NATURAL RESOURCE CONSERVATION COMMISSION

Protecting Texas by Reducing and Preventing Pollution -^

June 27, 1996 ^"-

.SENT VTA FAP.STMTT.F. FPRTTFTF.n MATT. •;.. _; •Mr. Chris Villarreal ':•," -.oRemedial Project Manager : .nCrystal Chemical Superfund Site —• '"°U.S. Environmental Protection AgencyRegion 6, 6H-ETAllied Bank Tower1445 Ross AvenueDallas, TX 75202-2733

RE: Explanation of Significant Differences,Crystal Chemical Site, Houston, Texas

Dear Mr. Villarreal:

This letter serves to communicate Texas Natural Resource Conservation Commission (TNRCC) concurrencewith the Explanation of Significant Differences (ESD) for the Crystal Chemical Superfund Site in Houston,Texas. The TNRCC believes that me remedial strategy for the ground water presented in me ESD issupported by the contingency measures outlined in the 1990 Record of Decision. Furthermore, the TNRCCagrees with the U.S. Environmental Protection Agency*s belief that the remedy utilizes permanent solutionsto the maximum extent practicable, is cost-effective, and remains protective of human health and theenvironment.

Please contact me with any questions concerning these comments or any other issues at the Crystal Chemicalsite at (512) 239-2030.

Sincerely,

E. R. (Trey) Collins. IllProject ManagerSuperfund Engineering SectionPollution Cleanup Division

ERC/erc

cc: Ms. Lisa Marie Price, U.S. Environmental Protecton Agency (6PD-NB)

P.O. Box 13087 • Austin, Texas 78711-3087 • 512/239-1000

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APPENDIX C

ADMINISTRATIVE RECORD INDEX

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Prepared for

United; States Environmental Protection Agency

Region 6

FINAL

Administrative Record AddendumIndex

CRYSTAL CHEMICAL COMPANY SUPERFUND SITEEPA ID No. TXD990707010

Explanation of Significant Differencesfor Record of Decision

ESS VIWork Assignment No. ESS06014

Chris VillarrealRemedial Project Manager

U.S. EPA Region 6

Prepared by

DPRA Incorporated717 North Harwood Street

Suite 1300Dallas, Texas 75201

P. 6214.0617March 19, 1997

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ADDENDUM

SITE NAME:SITE NUMBER:

CRYSTJ^L CHEMICAL COMPANY SITETXD990707010

DOCUMENT NUMBERDOCUMENT DATE:NUMBER OF PAGES:AUTHOR:COMPANY/AGENCY:RECIPIENT:

DOCUMENT TYPE:DOCUMENT TITLE:

007369 - 00739803/31/92030Michael C. Barra, Assistant Regional CounselU . S . EPA Region 6Charlotte L. Neifczel, Attorney for Southern PacificTransportation Company (Southern Pacific Lines), Law Firm ofHolrne Roberts & OwenCover Letter w/EnclosureSigned Administrative Order on Consent, Remedial Design forgroundwater remedy (Docket No, VI-11-92)

DOCUMENT NUMBER:DOCUMENT DATE:NUMBER OF PAGES:AUTHOR:COMPANY/AGENCY:RECIPIENT:


007399 - 00747009/03/92072Allyn M. Davis, Director, Hazardous Waste Management DivisionU . S . EPA Region 6David W. Long, Assistant General Counsel, Law Department,Southern Pacific LinesCover Letter w/EnclosureAdministrative Order, Docket No. VI-15-92, RemedialDesign/Remedial Action

DOCUMENT NUMBER:DOCUMENT DATE :NUMBER OF PAGES:AUTHOR:COMPANY/AGENCY:RECIPIENT:DOCUMENT TYPE:DOCUMENT TITLE:

007471 - 00768307/22/94213Industrial ComplianceConsultant for Southern Pacific Transportation Company-Southern Pacific Transportation Company and U . S . EPA Region 6Report, - Volume 1"Geochemical/Geohydrologic Report - Groundwater RemedialDesign"

DOCUMENT NUMBER:DOCUMENT DATE:NUMBER OF PAGES:AUTHOR:COMPANY/AGENCY:RECIPIENT:DOCUMENT TYPE:DOCUMENT TITLE:

007684 - 00835007/22/94667Industrial ComplianceConsultant for Southern Pacific Transportation CompanySouthern Pacific Transportation Company and U . S . EPA Region 6Report - Volume 2, Appendices 1-9"Geochemical/Geohydrologic Report - Groundwater RemedialDesign, Volume 2"

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ADDENDUM


CRYST.AL CHEMICAL COMPANY SITETXD990707010


008705 - 00926807/22/94564Industrial ComplianceConsultant for Southern Pacific Transportation CompanySouthern Pacific Transportation Company and U . S . EPA Region 6Report - Volume 3 , Appendices 10-15"Geochemical/Geohydrologic R.eport - Groundwater RemedialDesign, Volume 3"

DOCUMENT NUMBER:DOCUMENT DATE:NUMBER OF PAGES:AUTHOR:

COMPANY/AGENCY:RECIPIENT:


008351 - 00870408/17/94354Paul Kuhlmeier, Director of Remedial Technology, EnvironmentalAffairs GroupSouthern Pacific LinesLisa Price/ RPM, Superfund Enforcement Branch, U . S . EPA Region6Cover Letter w/Report"Treatment of Arsenic-Contaminated Groundwater from theCrystal --Chemical Superfund Site"

DOCUMENT NUMBER:DOCUMENT DATE:NUMBER OF PAGES:AUTHOR:COMPANY/AGENCY:

RECIPIENT:

DOCUMENT TYPE;DOCUMENT TITLE:

009269 - 00928109/28/94013John G. Bins, Project ManagerIndustrial Compliance (Consultant for Southern PacificTransportation Company)Lisa Price, RPM, Superfund Enforcement Branch, U . S . EPA Region6Cover Letter w/EnclosureRevised Work Plan for Technical Evaluation of ArsenicExtraction

DOCUMENT NUMBER:DOCUMENT DATE :NUMBER OF PAGES:AUTHOR:COMPANY/AGENCY:RECIPIENT:DOCUMENT TYPE:DOCUMENT TITLE:

009282 - 00931903/20/95038Hydrologic Consultants, Inc.Consultant for Southern Pacific LinesSouthern Pacific Lines and U . S . EPA Region 6Report"Treated Ground-water Reinjection Option Report"

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ADDENDUM


CRYSTAL CHEMICAL COMPANY SITETXD990707010

DOCUMENT NUMBERDOCUMENT DATE:NUMBER OF PAGES:AUTHOR:COMPANY/AGENCY:RECIPIENT:DOCUMENT TYPE:DOCUMENT TITLE:

009320 - 009510 -03/20/95191Hydrologic Consultants, Inc.Consultant for Southern Pacific Transportation CompanySouthern Pacific Transportation Company and U . S . ERA Region 6Report: - Volume 1"Soil and Groundwater Model Report"


009511 - 00984303/20/95333Hydrologic Consultants/ Inc.Consultant for Southern Pacific Transportation CompanySouthern Pacific Transportation Company and U . S . EPA Region 6Report - Volume 2 , Appendices A-H"Soil and Groundwater Model Report"

DOCUMENT NUMBER:DOCUMENT DATE:NUMBER OF PAGES;AUTHOR:COMPANY/AGENCY:RECIPIENT:


009844 - 00984504/20/95002E . R . (Trey) Collins III, Project ManagerTexas Natural Resource Conservation Commission (TNRCC)Lisa Price/ RPM, Superfund Enforcement Branch, U . S . EPA Region6LetterTNRCC comments about Southern Pacific Transportation Company*sgroundwater technical impracticability (TI) waiver for portionof remedy presented in "Assessment of the TI GroundwaterRemediation Report"



009846 - 00985004/28/95005Lisa Price, RPM, Superfund Enforcement BranchU . S . EPA Region 6David W. Long, Assistant General Counsel, Law Department,Southern Pacific Transportation CompanyCover Letter w/Enclosed CommentsEPA*s comments on the "TI Groundwater Remediation Report"

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DOCUMENT NUMBER;DOCUMENT DATE:NUMBER OF PAGES:AUTHOR:COMPANY/AGENCY:RECIPIENT:


009851 - 00985205/18/95002Christopher B. Amandes, Attorney for Theodore R. LevyVinson & ElkinsLisa Price, RPM, Superfund Enforcement Branch, U.S. EPA Region6LetterTI waiver and public notice requirements



009853 - 00985605/30/95004Lisa Price/ RPM, Superfund Enforcement BranchU . S . EPA Region 6Christopher B . Amandes/ Attorney for Theodore R. Levy/ Vinson& El kinsLetterResponse to Mr. Amandes' 05/18/95 letter

DOCUMENT NUMBER;DOCUMENT DATE:NUMBER OF PAGES;AUTHOR:COMPANY/AGENCY:RECIPIENT:


009857 - 00986006/19/95004Christopher B. Amandes, Attorney for Theodore R. LevyVinson ~£ ElkinsLisa Price, RPM, Superfund Enforcement Branch, U . S . EPA Region6LetterRequests EPA reconsider submitting decision granting SouthernPacific Lines a TI waiver for groundwater remedy



009861 - 00986808/30/95008Lisa Price, RPM, Superfund Enforcement BranchU . S . EPA Region 6Christopher B. Amandes, Attorney for Theodore R. Levy, Vinson& ElkinsLetter w/EnclosuresRe: 1) EPA grants TI waiver for groundwafcer remedy and 2) EPArequests access to property to perform response action forcontaminated groundwater

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DOCUMENT NUMBER;DOCUMENT DATE:NUMBER OF PAGES;AUTHOR:COMPANY/AGENCY:RECIPIENT:




DOCUMENT NUMBER;DOCUMENT DATE:NUMBER OF PAGES;AUTHOR:•



0098139 - 00987109/11/95003Christopher B . Amandes, Attorney for Theodore R. LevyVinson & ElkinsLisa Price, RPM, Superfund Enforcement Branch, U . S . EPA Region6LetterRequests EPA defer request for access to Mr. Levy's propertyuntil the agency has granted TI waiver to Southern PacificTransportation Company

009872 - 00987409/19/95003Lisa Price, RPM, Superfund Enforcement BranchU. S . EPA Region 6Christopher B. Amandes, Attorney for Theodore R. Levy, Vinson& El kinsLetterClarification of issues addressed in 09/11/95 letter aboutEPA's request for access to easement portion of Mr. TheodoreLevy * a property

009875 - 00987609/28/95002E.R- (Trey) Coll ins ZIT, Project ManagerTNRCCLisa Price, RPM, Superfund Enforcement Branch, U . S . EPA Region6LetterTNRCC's agreement with TI waiver and with the slurry wall

009877 - 00988810/02/95012 -Scott G . Huling, Environmental Engineer, Office of Researchand DevelopmentU . S . EPA, Ada/ OklahomaLisa Price, RPM/ Superfund Enforcement Branch, U . S . EPA Region6Memors-ndumReview comments on "Geochemical/Geohydrologic Report, VolumeI " , (07/22/94) and "Assessment of the TI of GroundwafcerRemediation, Volume 1" (95-R06-001)

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DOCUMENT NUMBER;DOCUMENT DATE:NUMBER OF PAGES;AUTHOR:



009889 - 00989110/26/95003Ca.1 James and Peter Feldman, Office of Emergency and RemedialResponseU . S . EPA HeadquartersLisa Price, RPM, Superfund Enforcement Branch, U . S . EPA Region6MemorandumReview of the "TI of Groundwater Remediation Report"

DOCUMENT NUMBERDOCUMENT DATE:NUMBER OF PAGESAUTHOR:COMPANY/AGENCY:RECIPIENT:


0098&2 - 009901 -11/11/95010Aniko Molnar, Environmental Project ManagerSouthern Pacific LinesLisa Price, RPM, Superfund Enforcement Branch/ U . S . EPA Region6Cover Letter w/Letter Report"Former Evaporation Pond - Source Removal Excavations"



009902 - 00990302/02/96002David W, Long, Assistant General Counsel, Law DepartmentSouthern Pacific LinesLisa Price, RPM, Superfund Enforcement Branch, U . S . EPA Region6LefcterSubmittal of "Assessment of the TI of Groundwater RemediationReport"


009904 - 01014602/02/96243Hydroldgic Consultants, Inc.Consultants for Southern Pacific Transportation CompanySouthern Pacific Transportation Company and U . S . EPA Region 6Report ~- Volume 1"Assessment of the TI of Groundwater Remediation"

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DOCUMENT NUMBER;DOCUMENT DATE:NUMBER OF PAGES:AUTHOR:COMPANY/AGENCY:RECIPIENT:DOCUMENT TYPE:DOCUMENT TITLE:

010147 - 01050302/02/96357Hydrologic Consultants, Inc.Consultant for Southern Pacific Transportation CompanySouthern Pacifid Transportation Company and U . S . EPA Region 6Report - Volume 2 , Appendices A-K"Assessment of the TI of Groundwater Remediafcion"

DOCUMENT NUMBER;DOCUMENT DATE:NUMBER OF PAGES:AUTHOR:

COMPANY/AGENCY:RECIPIENT:DOCUMENT TYPE:DOCUMENT TITLE:

010504 - 01050406/27/96001E . R . (Trey) Collins III, Project Manager, SuperfundEngineering Section, Pollution Cleanup DivisionTNRCCChris Villarreal, RPM, U . S . EPA Region 6LetterState concurs with Explanation of Significant Differences(ESD)


010505 - 01051506/27/96OilEPA StaffU . S . EPA Region 6PublicProposed ESDProposed ESD to the September 1990 Record of Decision


010516 - 01051907/08/96004UnspecifiedU . S . EPA Region 6PublicEPA Update on Activities at Crystal Chemical Superfund SiteSite Update

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010520 - 01054908/14/96030Christopher B. Amandes, Attorney for Theodore R. LevyVinson & ElkinsChris Villarreal, RPM, U . S . EPA Region 6Letter w/EnclosuresComments on behalf of Mr. Theodore R. Levy about proposed ESD


010550 - 01055208/19/96003Bruce DanielTerraNextChris Villarreal, RPM, U . S . EPA Region 6Facsimile Transmittal Cover Sheet w/EnclosuresSworn affidavit from the Houston Chronicle that ESD notice waspublished on 07/12/96.


010553 - 01055510/29/96003G . F . Shepherd, Director Environmental ProjectsSouthern Pacific Lines, Environmental Affairs GroupLisa Price, RPM, U . S . EPA Region 6LetterRebuttal to 08/14/96 Vinson & Elkins letter


010556 - 01058303/19/97028Jane N. Saginaw, Regional AdministratorU . S . EPA Region 6PublicDecision Document"Superfund ESD for Record of Decision: Crystal ChemicalSuperfund Site, Houston, Texas"

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[superfund explanation of significant differences for ... · the crystal chemical company superfund...

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